Patriot Viper II Sector 5 PC3 20000 Cas 9 4GB
 

When it came time to overclock the modules, the system was tapped out at 2500MHz on air. Maybe some sub-zero cooling could help these modules scale a bit higher. These modules will, however, run at lower speeds with tighter timings. Cas 6 was run at up to 1940MHz, Cas 7 to 2058 and surprisingly Cas 8 to 2490MHz. The only problem is to get the modules to scale, you need to bump up the TRCD setting in the memory sub-timings.

http://www.overclockersclub.com/revi...or5_pc3_20000/